Dublecco's Modified Eagles Medium/Nutrient Mixture Ham's F-12 (DMEM/Ham's F-12) was created after extensive study of Harry Eagle's first reports. Since then, studies have been underway to determine the media requirements for individual cell types. The medium found to be most satisfactory for these studies was a 1:1 mixture of Dublecco's Modified Eagle's Medium (DMEM) and Ham's F-12 Nutrient Mixture. To help compensate for the buffering capacity lost with the removal of serum, HEPES has been added in some modifications at a final concentration of 15mM.